Update on the GY 26" 337 Field Approval.

My application was turned down by the local FSDO because they want more data. They called me in for a meeting and showed me a new draft of AC43.13 Chapter 13 that deals with 'Tundra Tires' and spelled out all the data and testing they want me to pursue.

I guess I'll have to buy the tires and work on getting all that done. Heck, what's the difference between that and an STC? So, the saga continues.

gunny

Gunny wrote:Update on the GY 26" 337 Field Approval.

My application was turned down by the local FSDO because they want more data. They called me in for a meeting and showed me a new draft of AC43.13 Chapter 13 that deals with 'Tundra Tires' and spelled out all the data and testing they want me to pursue.

I guess I'll have to buy the tires and work on getting all that done. Heck, what's the difference between that and an STC? So, the saga continues.

gunny

Wow, what a bunch of horse shit!

Call Randy Long in Coleman to see if he can help. He's gotten them approved for a friends 180 and is reported to have a good relationship with the fsdo.

I've seen copies of the (semi?) official "tundra tire worksheet",
it calls out before-and-after weight and balance info,
plus flight tests at extreme forward & aft CG's.
Seems silly once it's been done on dozens if not hundreds of airplanes, but FAA seems to love creating hoops to jump through.
I bet there's been a lot of people who bought bushwheels just cause they didn't want to deal with the field approval BS.

I've had GY26's on my Husky for a few years now. They're holding up well, even on the grippy grooved concrete at KAUS.

One thing I was not happy with, though, were the tubes (Aero Classic?) that I got from Desser. They had a manufacturing fault that I didn't find till it became a slow leak. And the Desser guys were totally "sucks to be you" when I asked them to stand behind the sale.

Update on GY26 FA. After reviewing all the things I'd have to do... and flight tests I'd have to do... and money I'd have to spend to get this done. Balanced with the fact I'm not even convinced I want this tire to begin with. I think I'm just going to go with the AB 29" and the heavy tread. All in all, an easier proposition that going through the motions for this tire. Life is too short.

Oh, well. If anyone want to pick up the ball, I'd be happy to supply them with what I've done so far.

gunny

chrispo wrote: I've had GY26's on my Husky for a few years now. .........

Factory approved on the Husky, STC'd, field approved, or just installed under cover of darkness by Midnight Aviation?

Gunny wrote:Update on GY26 FA. After reviewing all the things I'd have to do... and flight tests I'd have to do... and money I'd have to spend to get this done. Balanced with the fact I'm not even convinced I want this tire to begin with. I think I'm just going to go with the AB 29" and the heavy tread. All in all, an easier proposition that going through the motions for this tire. Life is too short.

Oh, well. If anyone want to pick up the ball, I'd be happy to supply them with what I've done so far.

gunny

I just put a pair of AB heavy tread 29s on my wagon. Stupid expensive, but what a tire!

Scolopax-

Great recommendation, thanks for that!

And I agree, expensive, but given that the FAA wanted me to basically go through the STC process I'm not to sure the GY26's would have saved me any money at all. I'll keep my 800x6's and swap out:)

gunny

You two guys talking about the 29x10 (shaved or not) on ABW 10 rims, available from AA/Bushwheel,
or 29" Bushwheels with extra rubber?

Airframes Alaska now sells the 29" bush wheel with heavy tread. It costs $200 extra, but is probably worth it for us that have to make a lot of pavement landings.

gunny

We have a 180 and are looking at new tires, would love to do 29inch bushwheels but plan on a lot of beach and crosswind stuff. I know the stock tires throw a lot of rocks under the tail So how do the 29 in shaved air hawks wear. Has anyone gone wore a set out?
DENNY

Stirring the pot a little, the 180 was originally certified under CAR 3 wasn't it?

§ 3.362 Tires. A landing gear wheel may be equipped with any make or type of tire, provided that the approved tire rating is not exceeded under the following conditions:

(a) Load on main wheel tires equal to the airplane weight divided by the number of wheels,
(b) Load on nose wheel tires (to be compared with the dynamic rating established for such tires) equal to the reaction obtained at the nose wheel, assuming the mass of the airplane concentrated at the center of gravity and exerting a force of 1.0g downward and 0.31g forward, the reactions being distributed to the nose and main wheels by the principle of statics with the drag reaction at the ground applied only at those wheels having brakes. When specially constructed tires are used to support an airplane, the wheels shall be plainly and conspicuously marked to that effect. Such marking shall include the make, size, number of plies, and identification marking of the proper tire.
Note: Approved ratings are those assigned by the Tire and Rim Association or by the Administrator.

Source: http://www.navioneer.org/riprelay/Yet%2 ... _part3.pdf

Gunny wrote:Airframes Alaska now sells the 29" bush wheel with heavy tread. It costs $200 extra, but is probably worth it for us that have to make a lot of pavement landings.

gunny

The heavy tread 29" tires do weigh in at 34 lbs each, which is pretty heavy. I've heard it said that a pavement landing on bushwheels in a 180/185 costs $25.00 and I don't necessarily believe that it's an exaggeration. For me that's greater than a 25% increase in hourly operating expense assuming one pavement landing per hour. Giving this consideration, I work hard to avoid the pavement and activities that are known to cause wear, such as long pavement taxis and tight brake turns on tarmac. I have my strategies for not scuffing them often at home base, but out and about that can introduce unnecessary risks and piss off airport management.

DENNY wrote:We have a 180 and are looking at new tires, would love to do 29inch bushwheels but plan on a lot of beach and crosswind stuff. I know the stock tires throw a lot of rocks under the tail So how do the 29 in shaved air hawks wear. Has anyone gone wore a set out?
DENNY

29" airhawks are very heavy. Around 54lbs ea on ABW 10" if I remember right. In contrast, 29" ABWs on 6" 6 bolts are 38.5 llbs ea. For shits and giggles, the 8.5x10s on the ABW 10" are 45lbs ea and 8.5x6 on 3 bolts are about 25.5 lbs ea.

For me, there is no better tire than the 29" bushwheels.

DENNY wrote:We have a 180 and are looking at new tires, would love to do 29inch bushwheels but plan on a lot of beach and crosswind stuff. I know the stock tires throw a lot of rocks under the tail So how do the 29 in shaved air hawks wear. Has anyone gone wore a set out?
DENNY

The 29 Airhawks are super stiff. I checked some out installed on another airplane and there is almost no sidewall flex at all. They run these tires on 10000 lb Ag planes. Premature wear would not be a big concern for these tires.

Fiddler wrote:Stirring the pot a little, the 180 was originally certified under CAR 3 wasn't it?
§ 3.362 Tires. A landing gear wheel may be equipped with any make or type of tire, provided that the approved tire rating is not exceeded under the following conditions.......Source: http://www.navioneer.org/riprelay/Yet%2 ... _part3.pdf

Not sure if citing CAR 3 trumps the TCDS and/or manufacturer's specifications.
The original factory equipment list for my 53 C180 has items 201 (600x6 MLG wheels, standard or castering) and 202 (MLG tires 600x6- 6 ply or 800x6- 4 ply) marked as REQUIRED EQUIPMENT. As I understand it, to substitute different parts would require specific approval- such as an STC.

Bigrenna wrote:
29" airhawks are very heavy. Around 54lbs ea on ABW 10" if I remember right. In contrast, 29" ABWs on 6" 6 bolts are 38.5 llbs ea. For shits and giggles, the 8.5x10s on the ABW 10" are 45lbs ea and 8.5x6 on 3 bolts are about 25.5 lbs ea.

For me, there is no better tire than the 29" bushwheels.

Another data point: Heavy tread 29" Bushwheels on the aluminum ABI 6-Bolt wheels are 45lbs. Heavy tread 31s on the same wheels are 49lbs.


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I know the stock air hawk tires will wear well my question is how long shaved ones last?
DENNY

hotrod180 wrote:

chrispo wrote: I've had GY26's on my Husky for a few years now. .........

Factory approved on the Husky, STC'd, field approved, or just installed under cover of darkness by Midnight Aviation?

The 26 inch Goodyears are approved on the Husky Type Certificate. A logbook entry is all that's required.....and w/b update, of course.

MTV